Methylurea and Acetamide: Active Reabsorption by Elasmobranch Renal Tubules

Science  18 Dec 1964:
Vol. 146, Issue 3651, pp. 1587-1588
DOI: 10.1126/science.146.3651.1587


The renal tubules of the shark actively reabsorb urea. They also can reabsorb acetamide and methylurea, but there is no evidence for active reabsorption of thiourea. The specificity of the transport system thus appears to be different from the urea secretory system in the frog in which thiourea is secreted but acetamide and methylurea are not secreted.